Use front-end estimation with adjustment to estimate 6189 - 3674

Question

i dont know how to do this

 

Answer 1

We have 6189 - 3674

 

First look at only the far left digits  so call it 6000 - 3000 = 3000

 

Now for the adjustment:  Looking at the rest of the digits 189 would round to 200

                                                                                    674 rounds to 700

                                                                                    200 - 700 = -500

 

Now add that to the original result:

 

3000 - 500 = 2500

 

Our front end estimation with adjustment is 6189 - 3674 ≅ 2500